Procyanidins from Myrothamnus flabellifolia.
From the ethyl acetate soluble fraction of an acetone-water extract of the twig tips of Myrothamnus flabellifolia Welw. (Myrothamnaceae), a variety of flavan-3-ols (epicatechin, epigallocatechin and their 3-O-galloylated analogues) and procyanidins (DP <or= 3) were isolated and identified for the first time: Procyanidin B3 [catechin-(4alpha --> 8)-catechin], B4 [catechin-(4alpha --> 8)-epicatechin], B6 [catechin-(4alpha --> 6)-catechin] and catechin-(4alpha --> 8)-epigallocatechin along with the galloylated analogues B4-3'-O-gallate, procyanidin B2-3'-O-gallate [epicatechin-(4beta --> 8)-epicatechin-3-O-gallate], B2-3,3'-di-O-gallate, procyanidin B5-3,3'-O-gallate [epicatechin-3-O-gallate-(4beta --> 6)-epicatechin-3-O-gallate], catechin-(4alpha --> 8)-epigallocatechin-3-O-gallate, the trimer procyanidin C1-3''-O-gallate[epicatechin-(4beta --> 8)-epicatechin-(4beta --> 8)-epicatechin-3-O-gallate] and the new epicatechin-3-O-gallate-(4beta --> 6)-epicatechin-3-O-p-hydroxybenzoate. The structures were elucidated by 1D- and 2D-NMR experiments of their peracetylated derivatives, partial acid-catalysed degradation with phloroglucinol, ESI-MS and CD spectra.
Anke
Jennifer
J
Institut für Pharmazeutische Biologie und Phytochemie,Westfalische Wilhelms-Universität, Münster, Germany.
Petereit
Frank
F
Engelhardt
Claudia
C
Hensel
Andreas
A
D002942:Circular Dichroism; D009682:Magnetic Resonance Spectroscopy; D019684:Magnoliopsida / Q000737:chemistry*; D015394:Molecular Structure; D044945:Proanthocyanidins / Q000737:chemistry / Q000302:isolation & purification*; D021241:Spectrometry, Mass, Electrospray Ionization
D044945:Proanthocyanidins